See more synonyms for accelerator on
  1. a person or thing that accelerates.
  2. Automotive. a device, usually operated by the foot, for controlling the speed of an engine.
  3. British. any two- or three-wheeled motor vehicle, as a motorcycle or motor scooter.
  4. Photography. a chemical, usually an alkali, added to a developer to increase the rate of development.
  5. Also called accelerant. Chemistry. any substance that increases the speed of a chemical change, as one that increases the rate of vulcanization of rubber or that hastens the setting of concrete, mortar, plaster, or the like.
  6. Anatomy, Physiology. any muscle, nerve, or activating substance that quickens a movement.
  7. Also called atom smasher, particle accelerator. Physics. an electrostatic or electromagnetic device, as a cyclotron, that produces high-energy particles and focuses them on a target.
  8. Economics. acceleration coefficient.

Origin of accelerator

1605–15; 1930–35 for def 7; accelerate + -or2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for accelerator

Historical Examples of accelerator

  • Morse shoved the accelerator in and they were thrown back in their seats.

    The Hour of Battle

    Robert Sheckley

  • The plunging car, with accelerator full on, would be out of control.

    The Mind Master

    Arthur J. Burks

  • Cloud eased up his accelerator, eased down his mighty brakes.

    The Vortex Blaster

    Edward Elmer Smith

  • "Say not so," says Barry, steppin' on the accelerator careless.

    Torchy and Vee

    Sewell Ford

  • As soon as he was out of sight of his pursuers, he shoved down on the accelerator.

    Damned If You Don't

    Gordon Randall Garrett

British Dictionary definitions for accelerator


  1. a device for increasing speed, esp a pedal for controlling the fuel intake in a motor vehicle; throttle
  2. Also called (not in technical usage): atom smasher physics a machine for increasing the kinetic energy of subatomic particles or atomic nuclei and focusing them on a target
  3. chem a substance that increases the speed of a chemical reaction, esp one that increases the rate of vulcanization of rubber, the rate of development in photography, the rate of setting of synthetic resins, or the rate of setting of concrete; catalyst
  4. economics (in an economy) the relationship between the rate of change in output or sales and the consequent change in the level of investment
  5. anatomy a muscle or nerve that increases the rate of a function
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for accelerator

1610s, from Latin accelerator, agent noun from accelerare (see accelerate). Motor vehicle sense is from 1900.

Online Etymology Dictionary, © 2010 Douglas Harper

accelerator in Medicine


  1. One that increases rapidity of action or function.
  2. A nerve, muscle, or substance that quickens movement or response.
  3. A catalyst.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.